I apologize if this is not the correct place to post this, but I noticed that Wolfram Alpha was giving the wrong answer to the command
"row reduce row [[1, 2, 3], [4, 5, 6], [7, 8, 9]] mod 5"
which it gives the identity matrix as the answer. However, the matrix is not invertible. In fact, this should row reduce to [[1, 0, 4], [0, 1, 2], [0, 0, 0]]. It's null space is generated by [[1], [3], [1]].
Can anyone shed light on this? Is this actually a bug or is Wolfram Alpha misinterpreting the question?
